[Exim] How to get the queue-runner to unfreeze messages?

Greetings,

I have an application (see below for details) in which exim routes all
mail to a mail-relay. If mail-relay is down (e.g. refusing connections)
then messages are deferred, placed in the queue and re-tried. when the
mail-relay comes back, they get delivered. This is exactly what I want.

However, if the mail-relay is totally gone (e.g. exim can't even resolve
its IP address), then messages are frozen. Even after the mail-relay
comes back, the queue-runner doesn't attempt to deliver them, it just
says "Message is frozen". I can force delivery manually with "-qff", but
don't see how to make the queue-runner do this.

Any way to force the queue-runner to deliver frozen messages?

Rgds,

Owen Boyle.

Application details:

I am using exim-3.36 on a webserver behind a firewall. Exim receives
mail on localhost from CGI processes and routes all messages to a
mail-relay. The idea is that exim acts as a buffer, allowing fast
delivery from the CGIs (so they don't hang around waiting for an SMTP
session with the mail-relay). Also, if the mail-relay dies, exim will
queue the mails so nothing is lost and the CGIs don't die because they
can't send the mails.